Quick release hydraulic operator



July 5, 1932. WOODS 1,866,334

QUICK RELEASE HYDRAULIC OPERATOR Filed Nov. 6. 1930 Figl.

45 44 5 n 47 1 i l 46 Inventor: William J. Woods, y MAM His Atxlorney.

. Patented July 5, 1932 UNITED STATES PATENT OFFICE WILLIAM J. WOODS, OESCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, ACORPORATION OF NEW YORK QUICK RELEASE HYDRAULIC OPERATOR Applicationfiled November 6, 1930. Serial No. 493,902.

My invention relates to improvements in electro-hydraulicpressure-operated devices such as described in the copendingapplications of Walter O. Lum, Serial No. 193,016,

.5 filed May 20, 1927, and SerialNo. 415,341,

filed December 19, 1929, and assigned to the same assignee as thepresent invention.

The device referred to in the Lum application comprises a fluid cylinderin which is mounted a piston movable between an upper and lowerposition, the piston being biased to.

its lower position. An impeller pump within the casing is rotated bymeans of an electric motor to create a pressure in the fluid to raisethe piston. One of the difliculties encountered in the device,hereinafter referred to as an operator, is the inability of the operatorto instantly reset. This is due to the inertia of the rotor of thedriving motor and of the impeller and its associated parts. When thepiston has reached its upper or working position and the driving motoris deenergized to permit the piston to return to its initial positionthe inertia of the rotating rotor of the motor and the impeller causesthe impeller to continue to rotate for a short period of time and tocontinue to create a pressure on the underside of the piston, thusmaintaining the piston in its raised position until the energy ofrotation has been dissipated permitting the pressure to fall off and thepiston toleturn to its initial position. This prevents an immediatereset of the piston which action is desirable in certain types ofoperators.

Hence it is the principal object of my invention to provide an improvedtype of electro-hydraulic operator in which the effect of theinertiaupon instant reset is eliminated as much as possible.

In the preferred embodiment of my invention I provide a fluid casing inthe form of a cylinder which is vertically mounted. A piston is movablefrom its lower position to its upper position within the liquid andcarries an impeller pump for creating a pressure differential betweenopposite sides of the piston to raise the piston within the casing. Theimpeller pump is driven through a splined shaft which connects theimpeller pump and into the discharge side of the impeller pump.

When a pressure is created by rotation of the pump these bellows'expandto release the brake, thus permitting free rotation of the pump.Conversely, when the pump is deenergized and the pressure begins to fallthe bellows contract, permitting the pump brake to return quickly tobiased position to brake the rotation of the impeller pump. This permitsa quick reset of the piston without the time delay usually necessary todissipate the energy of the rotating rotor and impeller within the fluidin the casing.

In the accompanying drawing, Fig. 1 shows a cross section of thehydraulic .operator in the position of rest; Fig. 2 is a detailedshowing of the piston structure, and Fig. 3 is a detailed showing of thebrake mechanism.

In Fig. 1 the fluid casing or cylinder 10 which is filled with a fluidsuch as oil is provided with a covering or cylinder head 11 whichsupports the electric motor 12, the motor 12 being covered by means ofthe cupshaped member 13. A piston consisting of the parts 14 and15 ismounted to move in a vertical direction within the casing, the pistonbeing biased to its lower position. The two a portion 18 which formspartof the brake structure. The splined shaft 17 is provided with thebraking disc or element 19 which is positioned within the housing 18(Fig. 3) i A,

brake 20 is biasedinto-engagement with the braking element 1 9' b'yfmeans the spring 21 which is held in position by the washer 22.Connected to the opposite ends of the brake 20 are the bellows members23 and 21 which are screwed into the openings 35 and 31 in the topportion 15 of the piston. These bellows members are open to the exhaustof the impeller pump and are responsive to a pressure created by theimpeller pump to move the brake against the biasing spring 21 to permitfree rotation of the shaft 17.

The splined shaft 17 is mounted in the selfaligning bearing 25 carriedby the lower portion of the housing 18. This permits movement of thesplined shaft during operation of the operator so that should any slightmisalignment take place no stresses will be introduced into the shaft orthe pump housing formed by the piston.

The details of the pump housing as formed by the piston are shown inFig. 2. The piston consists of the two parts 1-1 and 15.. Passageways 26and 27 permit the fluid to enter the housing and contact with the upperpart of the impeller blades through the opening 28. The fluid is ledfrom the top part of the piston to the underside of the impeller bymeans of passageways such as 29 and 30 and the chamber 31. When theimpeller pump is rotated the oil entering the top and bottom parts ofthe pump housing is expelled by the impeller blades in a radialdirection through the openings such as 33 and 32 to the underside of thepiston thus creating a pressure on the underside of the piston to raisethe piston within the-cylinder. This pressure, of course, tends toexpand the bellows, as pointed out, to move the brake member 20 againstits bias.

The upper portion 15 of the piston carries the bushings 36 and 37 whichsupport the connecting rods 40 and ll which in turn support the bridgemember 42 carrying the workengaging eye 43. Stop members 38 and 39mounted above the supporting bushings 36 and 37 limit the upwardmovementof the piston. The connecting rods slide in the bearings l4 and15 mounted in the cylinder head and are provided with the slots 46 and47. It will be noted that clearance is provided around the connectingrods in the cylinder head so that no oil will loak over the outside ofthe casing. If any oil is carried past the bearings which act as wipersit will flow to the spaces 41 and 45 between the upper part of thebearings and the cylinder head and will then pass through the slots 16and 47 to the interior of the casing. The whole operator'is pivotallymounted by means of a pivot 4.8 on the bottom of the casing.

The operation of the device is as follows: lVhen the motor 12 isenergized the impeller ump 16 is rotated by means of the splined shaft17. The oil is led to the upper and lower sides of the impeller bladesby means of the passageways 26, 27 and 28 to-the upper side and 29, 30and 31 to the lower side and expelled through the exhaust passages 32and 33, thus creating a pressure on the underside of the piston. Thebellows members are quick to respond to this pressure and expand toforce the brake 20 against the biasing spring 21 to thereafterpermitfree rotation of the impeller pump and shaft. The piston will risewithin the cylinder until further movement is prevented by contact ofthe stop members 3S and 39 with the bearings 44 and 45. The piston willremain in the upper position so long as the impeller pump is rotated.

When the motor 12 is deenergized to permit the piston to return to itslower position the speed of the impeller pump begins to drop and hencethe pressure. A slight drop in the pressure on the underside of thepiston permits the bellows members to quickly collapse thus permittingthe spring 21 to move the brake member 20 into engagement with thebraking element 19 carried by the splined shaft 17. This action quicklybrings the pump and motor to rest which, of course, permits theimmediate return of the piston to its biased position. The brake actsquickly and thus eliminates the time delay due to continued operation ofthe pump which would otherwise take place due to the inertia of therotor of the driving motor and pump.

It will thus be seen by using my unique method for eliminating theeffect of inertia I provide a quick resetting hydraulic operator.Further, by placing all the parts within the oil in the fluid casingwear is reduced to a minimium, thus eliminating the necessity forconstant repairs.

The embodiment of the invention illustrated and described herein hasbeen selected for the purpose of clearly setting forth the principlesinvolved. It will be apparent, however, that the invention issusceptible of being modified to meet the different conditionsencountered in its use, and I, therefore, aim to cover by the appendedclaims all of the modifications within the true spirit and scope of myinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. A hydraulically operated device including a fluid casing, a pistontherein movable between two positions and biased to one of saidpositions, a pump for creating a pres sure within the fluid to move saidpiston to the other of said positions, a driving motor therefor, a brakefor said pump biased to a braking position, and means responsive to thepressure of said pump for releasing said brake, said brake acting tostop said pump immediately after de-energization of said motor wherebysaid piston will return to its biased position without delay.

2. A hydraulically operated device including a fluid casing, a pistontherein movable between two positions and biased to one of saidpositions, a pump for creating a pressure in the fluid to move saidpiston to the other position, a driving motor for said pump, a driveshaft operatively connecting said pump and motor, a braking membercarried by said drive shaft, a brake cooperating therewith and biased tothe braking position, and means responsive to the pressure created inthe fluid by said pump for releasing said brake, said'brake acting tostop said pump immediately after de-energization of said motorgwherebysaid piston will return to its biased position without delay.

3. A hydraulically operated device including a fluid casing, a fluidtherein, a piston movable in said fluid, a pump for creating a pressurein the fluid to move said piston, a

driving motor for said pump, a drive shaft operatively connecting saidpump and motor, a braking member carried by said drive shaft, a brakecooperating therewith and biased to the braking position, bellowsmembers in said fluid adapted to expand in response to pressure createdby said pump in said fluid, said bellows being connected to said brakemember'to release said brake member when said pump is-operated.

4. An electro-hydraulic operator including a fluid casing, a pistontherein, a pump for creating a pressure in the fluid to move saidpiston, an electric motor for driving said pump, a. drive shaftconnecting said pump and said motor, a brake for said shaft carried bysaid piston and biased to braking position, and means carried by saidpiston to release said brake and responsive to the fluid pressureexerted on said piston when said pump is operated.

5. An electro-hydraulic operator including a fluid casing, a pistontherein, a pump carried thereby for creating a pressure in the fluid tomove said'piston, an electric motor for driving said pump, a drive shaftconnecting said pump and motor, a braking member carried by said shaft,a brake cooperating with said braking member and biased to brakingposition, members carried by said piston responsive to the pressure ofsaid pump in the fluid, said members being operatively connected to saidbrake to release the brake in response to said pressure.

6. An electro-hydraulic operator including a fluid casing, a pistontherein movable between two positions and biased to one of saidpositions, all impeller pump for creating a pressure in the fluid tomove the piston to the other position, an electric motor for drivingsaid impeller pump, a driving shaft connecting said motor and said pump,a brake for said pump cooperating with said shaft and biased to abraking position, said brake being responsive to pressure created bysaid pump to move from its braking position to permit free rotation ofsaid shaft and pump, said brake immediately aftwithout delay.

er de-energization of said motor returning to braking position to stopsaid pump whereby said piston will return to biased position 7 Anelectro-hydraulic operator including a fluid casing, a piston therein,an 1111- peller pump carried by said piston for creatng a pressure inthe fluid to move the piston, an electric motor for driving saidimpeller pump, a splined shaft connecting said motor and said pump, abraking element carried by said splined shaft, a brake cooperating withsaid braking member and biased to the braking position, said brake beingresponsive to pressure created bysaid pump to move from its brakingposition to permit free rotation of said shaft and pump.

8. An electro-hydraulic operator including a fluid casing, a pistontherein movable between two positions and biased to one of saidpositions, an impeller pump housed in said piston for creating apressure in the fluid to move the piston to the other position, anelectric motor for driving said impeller pump, a driving shaftconnecting saidmotor and said pump, a brake for said pump cooperatingwith said shaft, means biasing said brake to braking position, bellowsmembers carried by the piston and operatively connected with said brake,said bellows members being .responsive to the pressure created by saidpump to move said brake against its bias to permit free rotation of saidshaft and pump, and upon a decrease in the pressure beneath said pistonwhen said motor is deenergized permitting said brake to immediatelyreturn to its braking position to render the inertia of said drivingmotor and impeller ineffective to maintain said pressure.

9. An electro-hydraulic operator including a fluid casing, a pistontherein, an impeller pump for creating a pressure in the fluid andhoused by said piston, an electric motor for driving said impeller pump,a splined shaft connecting said motor and said pump, a brake forsaidpump cooperating with said shaft and biased to a braking position,bellows members carried by said piston and operatively connected to saidbrake to movethe brake to an unbiased position in response to pressurecreated by said pump, said bellows members being open to the exhaustside of said pump whereby said bellows members will be instantlyresponsive to pressure changes when said pump is energized anddeenergized by said motor.

In witness whereof, I have hereunto set my hand this fifth day ofNovember, 1930.

' WILLIAM J. WOODS.

